Line-finder switch



- A. D. THOMAS LINE FINDER SWITCH Filed Aug. 31.

Inusu 012 HUI Eff Ell-Lamas at ease anon COP t OF CHICAGO it fit rarnanu i 1:

h iplicatioafiled a ua at, roar. atria Ito. aargawa. j

To all whom it may' co'noem:

Be it "known that I j ma Diismn Tnomms, a citizen of thefiep'ublic ofFrance, and a resident'of Paris France, have .invented certain new anduseful Improve ments in Line-Finder Switchesffor which ,applicationfwasfiled in France on June 17,

1920, No. 517,300) of which the "follow? ing is a specification. Thepresent invention relates to an apparatus whichhunts for a calling lineme at, Mt

til

of the batteryJ semi-automatic or automatic telephone system andconnectssaid line upto a selectindevice, sually, this class of apparatushas only one movement, that of rotation, a circumstance which'restrictsthe number of subscribers lines that can rapidly and siltciently huntedfor by a'Ksin le apparatus. The present invention pro'vi es anappara-'tus with two movements, viz; that oflitting followed byone of rotation,these two movements being obtained by the action of interruptersprings'operated by lifting and rotar the need or an impulse generator.e The call seeker being provided with several contact .banks--e ach for100 subscribers lines-is able to hun't for the subscrib'ers[ lines veryquickly, since 20 steps (IOlifting and 10 rotary) sufiice to con met the*subscribers linethat is furthest away from the normal position of theseeker to the next switch which is permanently connected'up with thecall seeker.

The accompanying drawing illustrates.

the circuit of a call seeker with 200 lines. It will be understood thatthis number can easily be increased b adding contact banks,

'wi ers anda relay or each bank added.

en the subscriber at .thecalling station takes .down his receiver, theprivate contact of the calling line is connected by a line relay to thenegative battery through the winding of the cut-oil relay (contact 64)The pilot relay connects (1) negative pole ing, in the ank of verticalcontacts, to

the row of horizontal contacts inwhich the calling line is situated(contact 55), and (k2) earth to the wire 72, which energizes t e relay Cthrough the contacts 1, 2, l and .5. The relay C operates the liftingmagnet E throng the circuit: earth, conmagnets, thus dispensing with,

with the contact correspond-' tacts 10, 9, 21,,20, 35, 34., 38, 37,48meta r The action of'the interrupter springs 48 and-49 causesthe magnetE to raise step by stethe shaft carrying the wipers.

hen the vertical wiper 50 reaches the contact connected to the negativepole of '64, the. relay corresponding to the wiper in contact withthenegative' pole of battery; s-energized' in the circuit: negative poleof the battery, winding 74, contact 64,

wiper 62, winding-of'relay A, contacts 43' 42;,- 33, 32, earth. Therelay A operates and opens the energizing 'CilGlllt of the magnet F "atthe contacts 9 and 10, at the contacts 1 and 2opens the circuit of therelay C, closes the contacts-1 and 3, earths the private wiper throughthe contacts 7 and 8,-

which kee s the cut-ofi rela 7 4 energized-.-, closes a olding circuitor the relay A through its second winding at the contacts 11 and'12; andconnects'upthe line wipers 67 and 68 to the wires 69 and 70, atitscontacts .14 and 15,16 and17. The calling line is thus connected up to'the 'selecting device, which, through the energiz of its line'relay inseries with-thecallers instrument, earths the WEB 71in order to,

hold the relay A in its operated position. It the calling line isinanother hundreds group, i. e. the line hunted for by the til tilwipers 61,65, 66, the relay B is then energized and connects the wipers65, 66 to the line 69, 70 over the contacts 24 and 25,

26 and 27., The relay 0, is slow-actin in order to keep the lead 71earthed orig enough to allow the relay of the selectin device to operateand to establish an eart connection with the said lead.

ven the rela C releases, it breaks the circuit of the re ay D, whichremoves the blocking potential over the'contact 55,'and thus enables thecalling lines in the same row of contacts to be hunted for byanotherseeker. .l[t completes the 0 crating circuit through the contacts 28 an29, to the neat V 5 select the group of linesin which acalling shaftcarrying the ,wipers. Oni reaching its normal position the shaftoperates the springs 44 and 45,."thus' breaking the cir- V cuit of therelease magnet,

, ing-line is located, a relay in sai .I'cla-im: I 7 1, In a finderswitch a plurality of wiper sets, groups and subgroups of calling linesto which said wipers have access, another wipertfor determining inwhatgrou a callswitch operable .upon initiation of a call -for.controllingsaid switch to move the'wipers to line is located, a relay in saidswitch operated when the proper group has been selected for causing saidswitch to simultaneousl hunt for a callingiline' in all subgroups of t eselected group, and other relays 1n I said switch one of which isoperated when a calling line is found to extend the calling line to anidle trunk line.

2. In a telephonexsystem, a, finder switch having primary and secondarymagnets and a plurality of sets of wipers, astarting re la adapted tocontrol the primary magnet when energized, a primary test relay forshifting the control of said starting relay to saidsecondary magnet atthe end of the "primary movement, a secondary test relay for-eachwiperset, and circuits for said secondary test relays closedsimultaneously by said primary test relay. I i In a telephone system, afinder switch to said secondary magnet at the end of the primarymovement, a secondary test relay for each wiper set, contacts on eachtest relay for connecting the line wipers of the associated set, testcircuits each including a secondary test relay and the test wiper of theassociated contact set, and contactson saidprimary testrelay for closingall said test circuits when the secondary movement begins. a

4. In a finder switch having primary and secondary magnets and a releasemagnet, a primary test relay controlling said primary magnet, and apluralit of secondary test relays jointly controlling said secondarymagnet and said release magnet.

5. In a finder switch, a primary test, relay, a plurality of secondarytest relays, a starting relay, and primary and secondary motor magnetscontrolled by all said relays jointlly.

6. n a finder switch, a primary. test relay, a, plurality of secondarytest relays,-a starting relay, primary and secondary motor magnets, anda circuit for said primary magnet controlled by all' said relaysjointly.

7. In a finder switch, a primary test relay, a plurality of secondarytest relays, a starting relay, primary and secondary motor magnets, anda circuit ,for said secondary magnet controlled by all said relaysjointly.

8. In a finder switch, a primary t'est'relay, a plurality of secondarytest relays, a

starting relay, primary and secondary motor magnets controlled by allsaid rela s-jointly, and a release magnet controlle 'ointly by saidsecondary test relays and said starting relay,

ALBERT DESIRE THOMAS.

